Invasive and implantable sensor devices have been developed in recent years which typically involve an indicator whose optical properties are altered in the presence of the analyte of interest. For example, fluorophores linked to a receptor capable of binding to the target analyte have been used as indicators in such sensors. A compound which comprises a combination of such a fluorophore and a receptor is known as a fluorescent sensor compound. Such fluorescent sensor compounds are known for both qualitative and quantitative sensing of analytes. The fluorescent sensor compounds may also comprise an anchor moiety which is capable of attaching the sensor compound to a substrate. For example, an anchor moiety may be capable of binding to, or being entrapped within, a hydrogel, with the hydrogel being incorporated within or onto an optical fibre which forms a part of sensing apparatus.
There is an ongoing need for novel fluorescent sensor compounds, for example based on novel fluorophore molecules, to be developed.